Since 1816, the Kazimierz Palace has served intermittently as the seat of Warsaw University (which was closed by the Russian Imperial authorities after each Uprising on the part of their Polish subjects, and in 1939-44 by the Germans).

Following the devastations wrought by the Deluge, the Villa Regia was rebuilt twice, in 1652 and 1660, to designs by Izydor Affait or Titus Livius Burattini, and came to be called the "Kazimierz Palace" for King John II Casimir, who favored it as a residence.[1]

Abandoned in 1667, the palace later became the property of King John III Sobieski. In 1695, the building was totally destroyed by fire.

About 1724, the property's ownership was transferred to King Augustus II. In this period were constructed an entrance gate at Krakowskie Przedmieście and eight barracks set perpendicularly to the palace façade.

In 1765, ownership was transferred to King Stanisław II August, who located the Corps of Cadets here following interior redesigns by Domenico Merlini. From 1769, the famous newspaper sponsored by the King, the Monitor, was printed in an establishment housed in an outbuilding of the palace. On April 5, 1769, the patriotic play Junak was presented on a Cadet Corps stage in the palace.[3]

In 1814, a fire destroyed the barracks before the palace, and in 1816 their place was taken initially by two side pavilions designed by Jakub Kubicki. That same year, the palace became the seat of Warsaw University. Concurrently, in 1817-31, it also housed the Warsaw Lyceum, a secondary school where Frédéric Chopin's father taught French and whose alumni included young Chopin himself.

The years 1818-22 saw expansion by two pavilions parallel to Krakowskie Przedmieście, designed by Michał Kado. In 1824, the palace was thoroughly rebuilt in the classicist style to the design probably of Hilary Szpilowski and Wacław Ritschel. About 1820, two further pavilions, a northern and a southern one, arose at the palace building itself.

In 1840-41, the next pavilion was built, designed by Antonio Corazzi, originally to be a secondary school and later serving as the seat of the "Main School" (i.e., Warsaw University). About 1863, the pavilions were rebuilt to designs by Antoni Sulimowski.

In 1891-94, in the yard between the palace and the Krakowskie Przedmieście gate, a library building was erected to a design by Antoni Jabłoński-Jasieńczyk and Stefan Szyller, and in 1910 a new Krakowskie Przedmieście gate was built. In 1929-31, the library building was rebuilt, and in 1930, the Auditorium Maximum building was erected to a design by Aleksander Bojemski.

During World War II, the Kazimierz Palace was destroyed, along with other Warsaw University buildings. It suffered during both the 1939 defense of Warsaw and the 1944 Warsaw Uprising. After the war, in 1945-54, the palace was rebuilt to a design by Piotr Biegański. The reconstruction of the whole campus was finally completed in 1960.

The Kazimierz Palace currently houses the Warsaw University rectorate, as well as the Museum of the History of Warsaw University. Since the building's revitalization in 2006 (partly with European Union funds), the building is one of the most attractive on Warsaw's Royal Route.